An optical imaging device has become an important tool to assess and diagnose diseases arising from luminal organs. Imaging methods/procedures including optical coherence tomography (OCT) and optical frequency domain imaging (OFDI) are two exemplary gastrointestinal tissue imaging methods. Other exemplary methods/procedures include confocal microscopy and spectrally-encoded confocal microscopy (SECM). OCT and OFDI procedures can acquire back-scattered light that comes from the refractive index mismatch of cellular and sub-cellular components, thereby facilitating the generation of images of at least one tissue microstructure in vivo. Comprehensive imaging, achieved by the helical pullback scanning of the imaging optics, can facilitate such microscopic imaging information to be obtained from entire sections of one or more luminal organs. Based on this microstructural information, diseases from the luminal organs, such as esophagus, colon, vessels, ducts, and so on, can be identified and detected in the early stages.
Optical tomography methods/procedures, including OCT and OFDI, can have a limited imaging depth range, e.g., from a few hundred micrometers to several millimeters. To obtain sufficient image contrast and resolution, the tissue should be located within the optical imaging range. In case of many luminal organs, which can have relatively large diameter (e.g., 5-8 cm for human colon, 2.5 cm for human esophagus, etc.), one preferable way to obtain images of the entire organ can be a centration of the imaging probe within the lumen.
One possibility for such centration can be to utilize a balloon catheter. After the placement of the catheter, the balloon can be inflated, thus resulting in the centration of the imaging optics. This procedure facilitates the imaging catheter to obtain the images from the entire epithelial tissues of the luminal organs. Since balloon can be inflated and deflated, and the balloon-catheter can be used as a standalone device or with the endoscope through the accessory channel.
However, the luminal organs can have complex structures thus causing the bending of the catheter and the decentering of the optical probe. This can cause the suboptimal imaging of the luminal organs. Some areas of the luminal organ may not be appropriately imaged when the decentering is greater than the imaging probe's imaging depth. Furthermore, due to the movement by the patient, which include breathing and heart beating, the bending issues and the associated decentering can occur frequently in a clinical setting, thus causing incomplete image acquisition.
Currently, a placement of the OFDI balloon catheter utilizes a sedated upper endoscopy procedure. Unfortunately, upper endoscopy can be a costly procedure. An important contributor to the high cost of endoscopy is the preference of sedation, which can force the procedure to be conducted in a specialized environment, with continuous cardiopulmonary monitoring and nursing support. Patient cost can be an additional factor, as sedation results in prolonged recovery times and loss of productivity.
In general when passing a catheter, transnasal access can be better tolerated than the transoral approach because of a more vigorous gag reflex encountered in unsedated transoral procedures. Standard transnasal procedures, such as nasogastric tube (NG tube) insertion, can be conducted in millions of patients annually, with few (if any) major complications. Unsedated, transnasal balloon dilation can be conducted in the outpatient setting, without complication, and is well tolerated. (See Rees CJ, “In-office unsedated transnasal balloon dilation of the esophagus and trachea. Current opinion in otolaryngology & head and neck surgery”, 2007; 15(6):401-4). Because the diameter of the balloon catheter is small enough to be threaded into the standard nasogastric tube, it can be also used for esophagus imaging procedures, without sedation.
Another form of the OFDI catheter facilitating unsedated procedure is a capsule that can be swallowed. The endoscopic capsule endoscopy (ECE) can be easier to administer than transnasal endoscopy and, since swallowing a capsule is familiar to patients, and it can be better tolerated than transnasal procedures. Conventional capsule endoscopy procedures likely have a lack of control of the capsule at the GEJ, however, thus possibly resulting in few viable images obtained at the critical region of the esophagus. Due to the decreased diagnostic accuracy and the high cost of the single-use, disposable capsule (e.g., about $450), the cost-effectiveness analyses for BE screening with capsule endoscopy have not demonstrated a benefit over conventional endoscopy. Another procedure, i.e., string capsule endoscopy (SCE) can be used, and which tethers the capsule with a string to enable strict control of the pill camera's location and repeated visualization of the GEJ. (See Weston AP, “String capsule endoscopy: a viable method for screening for Barrett's esophagus”, Gastrointestinal endoscopy. 2008; 68(1):32-4). A recent study in 100 patients with SCE showed that this technique is well tolerated and has a comparable diagnostic performance to that of upper endoscopy. For example, the SCE capsules can be retrieved, sterilized, and reused, thereby significantly decreasing the cost of the capsule endoscopy. Nonetheless, the SCE procedures are likely subject to the same diagnostic accuracy limitations as endoscopy, however.
An important characteristic of balloon catheters is the influence of the balloon on the tissue. In general, the centration balloon compresses imaged tissue, which can influence the diagnostic accuracy. The diagnostic process/procedure can be based on the structural differences that are characteristic for healthy and diseased tissues. Surface topology can be helpful in the analysis of the results, e.g., finger like projection in the epithelium is a typical feature for Barrett's esophagus. Additionally, a validation of the OFDI catheter imaging method/procedure can be performed by comparing the biopsy taken from the imaged region. It may be difficult to mimic exactly the same pressure conditions for the histology specimens.
Thus, it may be beneficial to address and/or overcome at least some of the deficiencies of the prior approaches, procedures and/or systems that have been described herein above.